Diagnosing conjunctivitis is based on the physical exam finding of a red, inflamed conjunctiva with associated tearing or other eye discharge. Diagnosing the underlying cause in order to provide correct treatment is sometimes difficult. Your veterinarian will probably perform the following: A thorough eye exam to detect any foreign material such as sand, plastic or grass. It can also detect any abnormal eyelid conformation, abnormal eyelashes, eyelid inflammation and disorders of the cornea.
An eye pressure test to detect glaucoma. This eye disease produces enlargement of the blood vessels under the conjunctiva and can easily be mistaken for conjunctivitis.
Schirmer tear test to determine if your dog's eyes produce an adequate amount of tears. Inadequate tear production results in keratoconjunctivitis sicca (dry eye), which causes conjunctivitis.
Fluorescein staining to reveal corneal lesions. The test is done by placing a drop of dye on the surface of the eye, then flushing so the eye can be examined. If stain is present on the surface of the eye, there has been disruption of the cornea, such as an abrasion, scratch or ulcer.
In addition to these tests, your veterinarian may recommend additional tests.
Conjunctival scraping and examination of the conjunctival cells to help identify the type of inflammation present
Certain blood tests if the animal is acting ill
Since many cases of conjunctivitis are mild and respond to topical anti-inflammatory medications, your veterinarian may chose to prescribe such a drug before proceeding with additional diagnostics. If the conjunctivitis does not resolve in five to seven days, or if it recurs immediately after the medication is stopped, further tests may be needed. For keratoconjunctivitis sicca or dry eye, artificial tears and lubricants are started. Topical antibiotics may also be needed initially to resolve any bacterial infection or concurrent corneal ulcer. In some cases, tear production can be increased with the use of topical cyclosporine. Treatment for dry eye is typically long term and repeated episodes of conjunctivitis may occur.
IF an exact cause can be determined, the specific treatment is instituted for that cause.
Conjunctivitis associated with upper respiratory infections are usually treated with topical antibacterial medications. Supportive care and oral antibiotics may be indicated for other symptoms.
Abnormal eyelid conformation usually requires corrective surgery. After surgery, the eye disease and conjunctivitis usually do not recur.
Abnormal eyelashes are treated with surgery, freezing or a form of cautery. Simply plucking the offending eyelash is not recommended as the eyelash will grow back and may grow in longer and more rigid than before.
Eye irritants such as pieces of sand, plastic, or grass can be flushed out of the eye using copious amount of sterile eye irrigation fluid. After removal of the offending foreign matter, a brief course of antibiotics and anti-inflammatories usually resolve the conjunctivitis.
Conjunctivitis due to environmental irritants can be difficult to treat unless the irritant can be removed. Owner's should avoid smoking around the dog, should avoid the use of spray carpet cleaners and other agents that might linger in the environment. Furnace and air-conditioning filters should be changed regularly, and air filter or humidifiers may be helpful in some cases. Follicular conjunctivitis usually responds to topical corticosteroids and the disease usually subsides as the dogs mature.
Corneal ulcers are generally treated with topical antibiotics and possibly pupil dilators. Many corneal ulcers heal within three to five days.
Allergy associated conjunctivitis is treated with topical antihistamines or topical steroids. This can alleviate some of the redness and inflammation. Removal of the item your dog is allergic to can also help eliminate the disease, but frequently this is not possible.
Inflammation of the eyelids and cornea must also be addressed.
Conjunctivitis associated with systemic illness in the dog often resolves as the dog's primary problem is corrected and the dog starts feeling better.